The report into HS1 by the National Audit Office looked at the reason given by the Department for Transport:
1.12 As we reported in our first and second reports on the project, international passenger demand fell far short of forecasts due to over-optimistic original forecasts. The Department and LCR have also attributed lower than expected demand to unforeseen developments such as competition from low-cost airlines.
It might be reasonable for the competition from low cost airlines to have been unforeseen in 1998. But having got the high speed demand wrong on one line already, you’d assume that the DfT weren’t going to make that particular mistake again.
However, the DfT and Hs2 Ltd seem determined not to learn from the lessons of the past.
Back in November, when the Transport Select Committee issued their report into High speed rail, they noted that HS2 Ltd had established challenge panels “to provide independent expert scrutiny on different elements of [its] work.”
During oral questioning, it was stated there were no aviaition representative on the challenge panels (since HS2 was announced in 2010, David Begg, the Director of Yes to HS2, has also become a director of BAA, and is now advocating for the third runway at Heathrow.)
http://www.publications.parliament.uk/pa/cm201012/cmselect/cmtran/1185/1185ii.pdf
q 377 “Steven Costello: May I add something which I hope is helpful? It is very difficult, in the way that HS2 Ltd has currently approached the proposal, to be definitive. In a way, it reflects the fact that HS2 Ltd had no aviation representative on the strategic challenge panel or any of the other challenge groups, so it is very much approached from a rail perspective. Certainly, from aviation’s point of view, it is the worst of all possible worlds at the moment, simply because a line from Birmingham, bypassing Heathrow, through central London to HS1 and Europe would be, in aviation terms, a thin route. There would not be enough traffic from point to point to sustain services at a frequency that is going to generate modal shift.
In fact, as the TSC noted,
“Of the three groups, currently comprising 22 people (all men), only the Analytical Challenge Panel contains any evident critic of high-speed rail. The Strategic Challenge Panel comprises eight transport and local government experts who are almost all publicly supportive of high-speed rail, including the Director of Yes to HS2, the Director of Greengauge 21 and the Chairman of Network Rail.”
It is only due to groups like Stop HS2 – which relies on volunteers and support from ordinary members of the public – that the HS2 plans are being publicly scrutenised at all.